All autopkgtests for the newly accepted makedumpfile (1:1.6.6-2ubuntu2) for eoan have finished running. The following regressions have been reported in tests triggered by the package:
makedumpfile/1:1.6.6-2ubuntu2 (i386, ppc64el) Please visit the excuses page listed below and investigate the failures, proceeding afterwards as per the StableReleaseUpdates policy regarding autopkgtest regressions [1]. https://people.canonical.com/~ubuntu-archive/proposed- migration/eoan/update_excuses.html#makedumpfile [1] https://wiki.ubuntu.com/StableReleaseUpdates#Autopkgtest_Regressions Thank you! -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to makedumpfile in Ubuntu. https://bugs.launchpad.net/bugs/1857616 Title: Cannot collect dump due to "Can't get a valid pmd_pte" error Status in makedumpfile package in Ubuntu: Fix Released Status in makedumpfile source package in Xenial: Opinion Status in makedumpfile source package in Bionic: Confirmed Status in makedumpfile source package in Disco: Invalid Status in makedumpfile source package in Eoan: Fix Committed Status in makedumpfile source package in Focal: Fix Released Bug description: [Impact] * Currently makedumpfile has 2 flaws due to: (a) out of synchronization with kernel code and, (b) kaslr handling. The first is related to a definition of a memory flag bit, whereas the second is about kaslr offset calculation - both cause similar failures when collecting the vmcore in kdump environment: Excluding unnecessary pages : [ 46.3 %] / __vtop4_x86_64[ 39.341233]: Can't get a valid pmd_pte. readmem: Can't convert a virtual address(ffffe05cb4000000) to physical address. readmem: type_addr: 0, addr:ffffe05cb4000000, size:32768 __exclude_unnecessary_pages: Can't read the buffer of struct page. create_2nd_bitmap: Can't exclude unnecessary pages. * The report is mainly related to the first issue, which started to happen after the merge of kernel commit 326e1b8f83a4 ("mm/sparsemem: introduce a SECTION_IS_EARLY flag"), introduced in kernel 5.3. After this commit, a memory flag was changed and induced the error in dump collection. The fix is available in makedumpfile, as commit 7bdb468c2c ("Increase SECTION_MAP_LAST_BIT to 4"). This is hereby SRUed to Bionic (due to HWE kernel 5.3), Eoan and Focal. * The other issue is fixed in both Eoan and Focal, on makedumpfile 1.6.6-based version. It is related with the kaslr offset: if the offset is small enough, we may return 0 wrongly in get_kaslr_offset_x86_64(), causing the vmcore collection to fail or even worse, to erase unintended data from the memory dump. This is fixed by makedumpfile commit 3222d4ad04 ("x86_64: fix get_kaslr_offset_x86_64() to return kaslr_offset correctly"), which isn't present in versions before 1.6.6. We hereby SRU this fix for Bionic. * Notice this modification is being worked concurrently with other kdump-tools' changes in LP #1828596. [Test Case] 1) Deploy an Eoan VM e.g. with uvt-kvm; 2) Set-up console output in the guest; 3) Install the kdump-tools package; 4) Configure and collect a dump (with sysrq to panic the system) - the error aforementioned is observed given Eoan kernel is 5.3-based. [Regression Potential] * The modifications hereby proposed are minimal and scope-constrained to makedumpfile in x86_64; both are merged in makedumpfile upstream, one of them being already released in E/F. An unlikely regression would potentially fails vmcore collection in kdump environment. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/makedumpfile/+bug/1857616/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
